From 6bb8904f65260d69b0382b6dea55ec52a16ba704 Mon Sep 17 00:00:00 2001
From: Daniel Schadt <kingdread@gmx.de>
Date: Tue, 9 May 2023 19:54:21 +0200
Subject: implement sorting for the browse page

---
 fietsboek/templates/browse.jinja2 | 10 ++++++++
 fietsboek/views/browse.py         | 53 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/fietsboek/templates/browse.jinja2 b/fietsboek/templates/browse.jinja2
index f8937bb..9860201 100644
--- a/fietsboek/templates/browse.jinja2
+++ b/fietsboek/templates/browse.jinja2
@@ -105,6 +105,16 @@
             {{ _("page.browse.filters.expand_advanced") }}
           </button>
         </div>
+        <div class="col">
+          <select class="form-select" name="sort">
+            <option value="DATE_DESC" {% if request.params.get("sort") == "DATE_DESC" %}selected{% endif %}>{{ _("page.browse.sort.date") }} &ShortDownArrow;</option>
+            <option value="DATE_ASC" {% if request.params.get("sort") == "DATE_ASC" %}selected{% endif %}>{{ _("page.browse.sort.date") }} &ShortUpArrow;</option>
+            <option value="LENGTH_DESC" {% if request.params.get("sort") == "LENGTH_DESC" %}selected{% endif %}>{{ _("page.browse.sort.length") }} &ShortDownArrow;</option>
+            <option value="LENGTH_ASC" {% if request.params.get("sort") == "LENGTH_ASC" %}selected{% endif %}>{{ _("page.browse.sort.length") }} &ShortUpArrow;</option>
+            <option value="DURATION_DESC" {% if request.params.get("sort") == "DURATION_DESC" %}selected{% endif %}>{{ _("page.browse.sort.duration") }} &ShortDownArrow;</option>
+            <option value="DURATION_ASC" {% if request.params.get("sort") == "DURATION_ASC" %}selected{% endif %}>{{ _("page.browse.sort.duration") }} &ShortUpArrow;</option>
+          </select>
+        </div>
       </div>
     </form>
   </div>
diff --git a/fietsboek/views/browse.py b/fietsboek/views/browse.py
index aed7d0a..1e97187 100644
--- a/fietsboek/views/browse.py
+++ b/fietsboek/views/browse.py
@@ -3,6 +3,7 @@ import datetime
 from collections.abc import Callable, Iterable
 from enum import Enum
 from io import RawIOBase
+from typing import TypeVar
 from zipfile import ZIP_DEFLATED, ZipFile
 
 from pyramid.httpexceptions import HTTPBadRequest, HTTPForbidden, HTTPNotFound
@@ -17,6 +18,8 @@ from sqlalchemy.sql import Selectable
 from .. import models, util
 from ..models.track import TrackType, TrackWithMetadata
 
+T = TypeVar("T", bound=Enum)
+
 
 class Stream(RawIOBase):
     """A :class:`Stream` represents an in-memory buffered FIFO.
@@ -57,13 +60,25 @@ def _get_date(request: Request, name: str) -> datetime.date:
         raise HTTPBadRequest(f"Invalid date in {name!r}") from exc
 
 
-def _get_enum(enum: type[Enum], value: str) -> Enum:
+def _get_enum(enum: type[T], value: str) -> T:
     try:
         return enum[value]
     except KeyError as exc:
         raise HTTPBadRequest(f"Invalid enum value {value!r}") from exc
 
 
+class ResultOrder(Enum):
+    """Enum representing the different ways in which the tracks can be sorted
+    in the result."""
+
+    DATE_ASC = "date-asc"
+    DATE_DESC = "date-desc"
+    LENGTH_ASC = "length-asc"
+    LENGTH_DESC = "length-desc"
+    DURATION_ASC = "duration-asc"
+    DURATION_DESC = "duration-desc"
+
+
 class Filter:
     """A class representing a filter that the user can apply to the track list."""
 
@@ -342,6 +357,36 @@ class FilterCollection(Filter):
         return cls(filters)
 
 
+def apply_order(query: Selectable, track: AliasedClass, order: ResultOrder) -> Selectable:
+    """Applies a ``ORDER BY`` clause to the query.
+
+    :raises ValueError: If the given order does not exist.
+    :param query: The query to adjust.
+    :param track: The aliased track class.
+    :param order: The order, one of the values given above.
+    :return: The modified query with the ORDER BY clause applied.
+    """
+    if order == ResultOrder.DATE_DESC:
+        query = query.order_by(track.date_raw.desc())
+    elif order == ResultOrder.DATE_ASC:
+        query = query.order_by(track.date_raw.asc())
+    # Thanks to SQLAlchemy, the join for the ORDER BY query is done
+    # automatically.
+    elif order == ResultOrder.LENGTH_DESC:
+        query = query.order_by(models.TrackCache.length.desc())
+    elif order == ResultOrder.LENGTH_ASC:
+        query = query.order_by(models.TrackCache.length.asc())
+    elif order == ResultOrder.DURATION_DESC:
+        query = query.order_by(
+            (models.TrackCache.moving_time + models.TrackCache.stopped_time).desc()
+        )
+    elif order == ResultOrder.DURATION_ASC:
+        query = query.order_by(
+            (models.TrackCache.moving_time + models.TrackCache.stopped_time).asc()
+        )
+    return query
+
+
 @view_config(
     route_name="browse", renderer="fietsboek:templates/browse.jinja2", request_method="GET"
 )
@@ -357,7 +402,11 @@ def browse(request: Request) -> Response:
     # Build our query
     query = select(track).join(models.TrackCache, isouter=True)
     query = filters.compile(query, track, models.TrackCache)
-    query = query.order_by(track.date_raw.desc())
+
+    order = ResultOrder.DATE_DESC
+    if request.params.get("sort"):
+        order = _get_enum(ResultOrder, request.params.get("sort"))
+    query = apply_order(query, track, order)
 
     tracks = request.dbsession.execute(query).scalars()
     tracks = (TrackWithMetadata(track, request.data_manager) for track in tracks)
-- 
cgit v1.2.3